“You’re not so aware either,” suggested Elk. “And now I’ll tell you something: we’ve had Number Seven under lock and key since morning—now laugh!” To his amazement the man’s face relaxed in a broad grin. “Bluff!” he said. “And cheap bluff. It might deceive a poor little thief, but it doesn’t get past with me. If you’d caught ‘Seven,’ you wouldn’t be talking fresh to me. Go and find him, Elk,” he mocked, “and when you’ve got him, hold him tight. Don’t let him get away—as Mills will.” Elk returned from the interview feeling that it had not gone as well as it might—but as he was leaving the station he beckoned the chief inspector. “I’m planting a pigeon on Hagn this afternoon. Put ’um together and leave ’um alone,” he said. The inspector nodded understandingly. CHAPTER XVII THE COMING OF MILLS ON the morning that Elk waited for the arrival of the informer, elaborate precautions were being made to transfer the man to headquarters. All night the prison had been surrounded by a cordon of armed guards, whilst patrols had remained on duty in the yard where he was confined. The captured Frog was a well-educated man who had fallen on evil times and had been recruited when “on the road” through the agency of two tramping members of the fraternity. From the first statement he made, it appeared that he had acted as section leader, his duty being to pass on instructions and “calls” to the rank and file, to report casualties and to assist in the attacks which were made from time to time upon those people who had earned the Frog’s enmity. Apparently only section leaders and trustees were given this type of work. They brought him from his cell at eleven o’clock, and the man, despite his assurance, was nervous and apprehensive. Moreover, he had a cold and was coughing. This may have been a symptom of nerves also. At eleven-fifteen the gates of the prison were opened, and three motor-cyclists came out abreast. A closed car followed, the curtains drawn. On either side of the car rode other armed men on motor-cycles, and a second car, containing Central Office men, followed. The cortège reached Scotland Yard without mishap; the gates at both ends were closed, and the prisoner was rushed into the building. Balder, Elk’s clerk, and a detective-sergeant, took charge of the man, who was now white and shaking, and he was put into a small room adjoining Elk’s office, a room the windows of which were heavily barred (it had been used for the safe holding of spies during the war). Two men were put on duty outside the door, and the discontented Balder reported. “We’ve put that fellow in the waiting-room, Mr. Elk.” “Did he say anything?” asked Dick, who had arrived for the interrogation. “No, sir—except to ask if the window could be shut. I shut it.” “Bring the prisoner,” said Elk. They waited a while, heard the clash of keys, and then an excited buzz of talk. Then Balder rushed in.